A Harbor City man who joked about running a business he called OPM Capital Group - for "Other People's Money" - has been charged with stealing $600,000 from three clients, costing a married couple their home and life savings, a detective said Thursday.

Mario Alexander Hernandez, 57, a licensed real estate broker who formerly ran an office at 24205 Narbonne Ave. in Lomita, was arrested Tuesday at his home. Charged with three counts of grand theft, Hernandez made his first court appearance Wednesday in downtown Los Angeles. He was jailed on $600,500 bail.

According to sheriff's detectives, Hernandez prepared tax returns for clients in addition to working as a real estate broker, but falsely claimed to be a certified public accountant and former Internal Revenue Service employee.

From March to December 2007, Hernandez allegedly convinced a married couple and another client to invest the funds from their 401(k) Individual Retirement Accounts into his company, OPM Capital. He promised to invest their money in a mix of stocks, bonds, mutual funds and real estate, and told them they would receive returns of 10 to 20 percent.

"He allegedly told them, `I'll even make your mortgage payments with the proceeds,"' Derry said. "He convinced them to roll their entire life savings over to his company. They ended up getting their house foreclosed."

A Sheriff's Department Real Estate Fraud Team investigation found that Hernandez allegedly used the clients' money on residential construction projects in Harbor City; to pay previous "investors" and an attorney; for gifts and loans to family members; for personal and business expenses, including his life insurance and cellphone bills; to pay his office rent, employee salaries and health plans; to buy office supplies; and to pay the mortgages on several other properties.

Derry said the money was depleted by October 2008.

"He did do real estate transactions, but, according to what we found, he made promises to investors to do certain things with their money and he didn't do them," Derry said. "It looked to us he was basically running his business off the money of these people."

In the summer of 2008, the clients began asking questions, but Hernandez strung them along, Derry said. The Wilmington couple began receiving notices that they faced foreclosure on their home, and eventually lost the house.

Detectives only recently were able to investigate the case because the husband was suffering medical problems stemming from the ordeal.

"They had to move in with their kid," Derry said. "The husband of the couple that got evicted was so distraught he had to go into psychiatric care because of the depression and he was not able to work with us because he was so distressed."

Prosecutors will seek restitution during the court process, but Derry said the victims will never earn back what they lost.

None of the victims knew what OPM stood for, the detective said.

"According to one of his employees, (Hernandez) thought it was a joke," Derry said.

Detectives suspect Hernandez might have more victims and want to talk to anyone who had financial dealings with him.

Anyone with information about him is asked to call Derry at 562-233-8204.